Electric signal system



May 23, 1933. T. H. THOMAS 1,910,575

ELECTRIC SIGNAL SYSTEM Filed March 9, 1 929 I w l I m i E 1% g 5 m u STROKE BELL INVENTOR THOMAS H.THOMA$ ATTORNEY Patented May 23, 1933 UNITED STATES ren't orrice I V .I/":' THOMAS H. THOMAS, or; EDGEWQOD, PENNSYLVANIA, .assrcnon TO THE wns'rnw EoUs'n'AIB, BRA g or PENNSYLVANIAi rimmed men March 9,

This invention relates to an electric train signal system, in which'the engineer may signal a trainman or a trainman may signal to the engineer.

One object of my invention is to provide an electric train signal system in which a source of current is provided only on the cars and in which a signal device operating under a small amount of electric power is provided on the locomotive.

Another object of my invention is to provide an electric train signal system in which a trainman may signal to the engineer from a car on which the signal system has been cut out of action.

Anotherobject of my invention is to provide an electric train signalsystem in which the trainmanmay receive a'signal from the engineer when the signal system on the car is cut out;

Other objects and advantages will appear" in the following more detailed description of the invention.

In the accompanying drawings,-F1g. 1 1s a diagrammatic view of an electric train signal system as applied to a locomotive and two cars of the train, and showing my invention embodied therein; and Fig. 2 is an enlarged elevational view, partly in section, of a signal gong with the cover removed.

The signal system shown in the drawings is of the type employing a single train wire 1, with the return circuit through ground. On each car of the train, a source of electric 35 current 2 is provided, which may conveniently be the storage battery used for the lighting system.

The positive terminal of the source of current is connected to a wire 3, containing a signal device 4, which may be of the singlestroke gong type and which operates to sound a signal when the signal system is deenergized. The gong is of the well known type and comprises a coil 1* which when energized, attracts a magnet armature 4 which constitutes a resilient hammer arm that is pivoted for oscillation about a pivot shaft 4. A spring 4 serves to move the hammer to strike the bell or gong 4 when the magnet coil is deenergized and releases the armature. Re-

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energization of the coil returns the hammer to its retracted position shown in full lines.

A current rectifier 5 may be included in the circuit to prevent flow of current except in the directionot the arrow, so-that if there should exist any difference of potential of the batterieson other cars, the generator oil-anyone car will not operate to charge the batteries-on other cars of the train.

Amanu'ally controlled switch device 6 is provided on each car, comprising a casing containing a plunger 7 of insulating material on which aremounted contact rings 8 and 9-. A'stem 10 extends upwardly from the plunger 7 and is adapted to be engaged by adouble lever l1,-so arranged that when the cord 12 is pulled, the lever will be actuated to depress the stem 10.

A spring 13 acts on the lower end of the plunger 7 and urges the plunger to its normal position, as shown in the drawings, in which the contact ring 8 connects wire 14, with a wire 15, connected to the train wire 1. A cut out or elevator switch 16 is provided and when the signal system on the car is cut in, the switch 16 is in the position of the switch 16 Shown at the left of the drawings,

in which the wire 14 is connected to wire 3.

The second position of the switch is deterwith a movable stop-17,1iormally maintained in position by a spring 18. The third position of the movable stop is determined by the engagement of the lower end of the plunger with the screw plug 19.

On the locomotive, there is provided a magnet valve device comprising an electromagnet 20 and double beat valves 21 and 22 adapted to be operated upon energization and deenergization of the magnet. A source of fluid under pressure, such as the reservoir 23, is connected to valve chamber 24 and a whistle 25 is connected to valve chamber 26. The space intermediate the valves 21 and 22 is connected to a reservoir 27.

One terminal of magnet 20 is connected by wire 28 to the train wire 1 and the other terminal is connected, through a switch 29 with the ground. A. shunt circuit wire 30 with an adjustable rheostat 31 is provided,

through the signal device 4, wire 3, switch 16, wire 14, contact ring 8, wire 15, train wire 1, wire 28 on the locomotive, magnet 20 through switch 29 to ground.

The magnet 20 on the locomotive will thus be normally maintained energized, so that the. valve 21 will be held seated while the valve 22 will be unseated.

With the valve 22 unseated, the reservoir 27 will-be charged with fluid under pressure, as supplied past the open valve 22 from the reservoir 23.

If the engineer wishes'to signal the trainman on a car with the switch 16in the cutinposition, he opens the switch 29 and thereby'the, train wire circuit. The magnet 20 on the locomotive is thus deenergized and the valve 22 isthen seated by spring 32 while valve 21 is unseated. With valve 21 unseated, fluid under pressure is supplied from the reservoir 27 to the whistle 25, which is then sounded to indicate to the engineer that the signal system is working.

On a car with the switch 16 in the cut-in position, asshOWIl in the drawings, the signal.

bell device 4 is deenergized and thus sounds asignal. After making a signal, the engineer allows the normally closed switch 29 to close and if the trainman wishes to signal the engineer, he pulls a signal cord 12 so as to operate the lever 11 to depress the plunger 7 The plunger is depressed to the second signaling position, wherein it engages the stop-17 and the switch 8 is open and interrupts the circuit through the switch 16,

I thereby causing sounding of the signal 4.

The train wire 1 is therefore grounded through contacts 37, 36 and 35. The magnet 20 is therefore shunted from the circuit including a battery 2 and being thus deenergized, the Whistle 25 is sounded in the manner hereinbefore described.

After the trainman has signaled the engineer, he permits the switch plunger 7 to return to its normal position, in which position the engineer may again signal the trainman, if he so desires.

The cut-out or selector switch 16 is provided, so that on a particular car, such as a sleeping car where the sounding of a signal might disturb the passengers, the signal apparatus may be cut out of action by moving the switch 16 to the cut-out position as on the second car.

wish to he may shift the plunger 7 At this time, the signal magnet 20 is energized by batteries 2 in other cars through circuits including the switches 16 that are in the cut-in position. Such circuits may be considered auxiliary circuits for energizing the coil 20 when a battery is ,cut out of the circuit by itsrespective switch 16.- when it is in cut-out position. In such cases, however, the trainmanniay signal tlie engineer, inf ah--eln'1e'r-' gency, without taking thetime to t p w the switch 16 to its cut-imposition. Tliis-isprO- vided' forin the present system, since with the switch 16 in cut-out position, the 7' tramman inaysig'nal the engineer by depressing the plunger 7 to the second signaling position. hereinbefore referred to, and ,inv

which thetrain wire1 is connectedto grouiid through contacts 37, 36 and 25,510. asto cause the; deenergization V of- .the magnet 20. ,on the locomotive. In this case, however, the trainman isinforined. ,thatthesignal system is operative, by the soundingofthe signal 4 in: cident to the momentary energization-and subsequent deenergization-of a secondary ciri cuit. through the signal 4 and switch;,16 to ground when the switclr contact ,ring 9 momentarily engages thegcontact- 33 and closes the circuit through switch 16 and contact 35 to ground, as the switch plunger ,7 is

moved to the second signaling position wherein the ring is out of engagement with the contact .33 and just below, it,

As. indicated'in Fig, 1, whenthe switch plunger 7 is in its normal position, the contact ring 9 is normally out of engagement with the contact 33 and-accordingly ,the circuit through the signal 1 is open andnocurrent fiows through thesignal device from its associated battery while the switch16 is in the cut-out position and the signal magnet 10 is shunted from the circuit due toits connection to ground as .above described. When the switch plunger 'Tis in its normal position and the switch 16 is in the cut-in position, the.

magnet .coil 20 is connected in series with the signal 4 and the high resistance of the coil 20 limits the flow of current from the battery to a negligible quantity.

If the trainman wishes. to receive a responsive signal from the engineer without moving the switch 16 back to its cut-in position,

to its third signaling position, in which the contact ring 9 connects contact '38 connected to wire 3,

with contact 37. The signal device 4 on the car is thus connected to the train wire 1, so that if the engineer opens the switch 29, the signal device ion the car will be deenergizcd to solnid a signal.

It will now be seen that with the improved signal systeni, a trainman. may signal the engineer from a car where the signal apparatus is cut out and the trainman may also receive a signal from the engineer.

5 sincet-he magnet 20 is responsive to a small amount of current Whereas a direct electrically coiitrollcdsignal device requires a r'ela-' operation y While=one illustrativeembodiment of the invention' has' been described in detail, it is not 'my'intention to limit its scope to that embodiment or otherwise than by the terms rule appended claims.

Hating now described my invention, what I claim a'sne'w anddesirej to secure by Let tors" *P'aitc'nt, is i y 1; In an-electridtrain signal system, the combiiia'tionivith an electric train vvire and a ground conductor, of a signal device on a power vehicle of a train comprising elcctrically controlled means operated upon deenei'gizatioii to give a. signal and having one terminal connected to' said train wire and the other terminal to the ground conductor, a signal'apparatus on each of a plurality of cars of the train comprising electrically controlled means operated upon deenergization to 'givea signal and connected between the train'wi'res and ground conductor, and a sit irce'o'tcurrent on each car connected in serie'sto'the ground conductor, its respective signal apparatus and to said train wire, a cut-out switch for connecting and disconnecting said signal apparatus and source of current to and from said train wire, and a manually operated switch on each car for conn ectingthe said train wire to the ground conductor.

fZQ'In an electric train signal system, the combination with an electric train wire and agroundconductor, a signal device on a power vehicle of a train comprising electrically controlled means operated upon deencrgizatiou to a signal and normaliy conii -acted to said train wire and to the ground tively -lie'avy current to ensure satisfactory conductor, and signal devices on cars of the train, each comprising electrically controlled me as operated upon deenergization to give a sgnaland connected between the train wire and the ground conductor. of a source oii cnrrent on each car in series with the car signal, device. and connected between the train wire and the ground conductor, a cutout switch on each car for connecting and disconnecting both the car signal device and the source of current on the car to and from the train wire, and a manually operable switch on each car for grounding the train wire to .deenergize the signal device on the power vehicle,independently of the position of the cut-out switch.

3. In an electric train signal system, the combination with an-electric train wire and aground conductor, of afsign al device bn-a power vehicle of'a train comprising elec trically controlled means operated upon de energization to give a signal and having'ond terminal connected to said train wire andthe other terminaltothe groundconductor, a signal apparatus on each of a plurality of cars of the train'comprising -electrically controlled means operated upon 'deenergizw tion- -to-give a signal and connected between the train wire and the ground conductor, and

a. source ofcurrent connected between the signal apparatus and said train wire, sentout switch for connecting and disconnecting said signal and source of current to and from said train wire, and a manually operated switch on each car having one position for connectingthe car signaldevice and the associated source of current to said train Wire'and another position'for connecting the train wire to ground.

4. In an electric train signal system in eluding electric circuits, a signal device one I power vehicle of a train comprising electrically controlled means operable upon deenergizatlon to give a signal, a signal device on a car of a train comprising electrically controlled means operable upon deenergiZation to give a signal, asource ofelectriccurrent onsaid car in series with the car' signal, a switch device on the car havino a position for closing a circuit including saidsource of current and the signal devices on the power vehicle and the car and-a position for deer!- ergizing said circuit and for preparing a circuit through the signal device on the car for completion byanother switch, and another switch device on the car having one'position in which the source of current and the signal device on the car are connected to said circuit and another position in which the source of current and the signal device on the car are disconnected from said circuit and in which the signal device on the locomotive is shunted from the circuit through the source of electric current.

5. In an electric train signal system, an electric circuit, a signal device on a power vehicle of a train included in said circuit and comprising electrically controlled means 0perable upon deenergization to give a signal, a signal device on each of a plurality of cars of the train, each comprising electrically controlled means operable upon deenergization to give a signal, a source of electric current on each car connected in series with the car signal, a cut-out switch On each car operative in one position to connect said car and power vehicle signal devices and sourc of current into said circuit and in another position to disconnect said source of current and said car signal device from said circuit, and a manually operahle switch on each car for shunting the signal device on the power vehicle from said circuit.

,;6,.1In-.; an electric gtrainw signal 1 system l1aving. a train .w.1 re-, an d&a ground-c011 ducto yfa signals device .on a 5 ,power vehicle} of a train iconiprising .electrica1ly- --controlled-means connected between th'eitrain wire and the ground conductor and operable upon deenergization. to give asignal,

a Signal 5 devic i0 each. at at; ea t it e e t e t a ns e hQQ pr si-na e tr. s a .y controlled means operable upon deenerg1za tionto giveasignal a source/ ot current in series with each year sign al and connected to n p s ion nswlii h t sense. o cu n nd t e. e s gna ar d conne e; .frOm said train w 1r e. and -a manually ,operable switch device on each of said cars haying one V positioniin which the source 0f} current and Q-MtisiQ l de ce ar a ct d to s i train .wiie and Ianothen ,positi on in which said train; wire is connectedto the ground conductor, thereby, shunting the circuit through the signal deviceon the power ve- In' an electric signal system for trains, ercombination with an electric circuit includinga sourceof electric current, ot a plurality, of, current responsive signaldevices.

connectedgin the circuit and operative to signal vwhen .deenergized, a signal switch for nonmallymaintaining the circuit closed, a selector switch for selectively connecting the signal devices and the signal switchin series relation or ior shuntingone ofthe signal devices and the signal switch irom the circuit.

,8 In anelectric signal system for trains, the combination with an electric circuit including a sourceof electric current, of a plurality I of current responsive-signal; devices connected in the circuit and operative to signormally maintaining the circuit closed a selector switch for selectively connecting the signal devices and the signal switch in series relation or for shunting one of the signal devices and the signal switch from the circuit while preparing a secondary circuitthrough the other signal device for completion by another switcl1,-and a normally open switch in the secondary circuit.

9. In an electric signal systeinfor trains, the combination with an electric circuit includinga source of electric current, of a,plurality of current responsive signal devices connected in the circuit and operative to signal when deenergized, a signal switch for norm-ally maintainingthe circuit closed, a selector switch for selectively connecting the signal devices and the signal switch in series relation or for shunting one of the signal devices and the signal switch from the circuit while preparing a secondary circuit through the other signal device for completion by another switch, means for establishing an auxiliary circuit through the shunted signal device and signal switch and a second normally open Signal switch in the secondary circuit adapted when moved to an operative signalling posit-ion to alternately energize and deenergize the secondary circuit to actuate the signal device therein and to shunt the previously shunted signal device andsignal switch from the auxiliary circuit to cause its deenergization. i

10. In an electric signal system for trains, a pair of conductors, a current supply means for supplying current to the conductors, a. current responsive signal device on the locomotiveof the train operative when deenergized to give a signal and connected across the conductors, a signal switch on the locomotive for interrupting the circuit through the signal device, a plurality of current responsive signal devices on the cars of the train connected across the said conductors and operative when dcenergized to give a signal, and a selector switch on each car for selectivey connecting the car si nal devicesin circuit with the locomotive signal devices and the said sup ply means whereby the car signal deri es are under the control of the signal switch on the locomotive, or shunting the locomotive signal device and the locomotive goal switch from the circuit containing its pective signal device 11. In an electric signal system for trains, a pair of conductors, a current supply means for supplying current to the conductors, a current responsive signal device on the locomotive of the train operative when deenergizod to give a signal and connected across the. conductors, a signal switch on the locomotive for interrupting the circuit through the signal device, a plurality of current reponsive signal devices on the cars of the nal when deenergized, a-signal switch for and the said supply means whereby the car signal devices are under the control of the signal switch on the locomotive, or shunting the locomotive signal device and the locomotive signal switch from the circuit contain- .ing its respective signal device, and switch means on each car in the circuit containing the. signal device thereon, for interrupting the circuit through the signal device on the car and for shunting the signal device on the locomotive from the circuit through the said current supply means regardless of the operative position of the selector switch.

12. In an electric signal system for trains, a. pair of conductors, a current supply means for supplying current to the conductors, a

current responsive signal device on the locomotive of the train operative when deener gized to give a signal and connected across the conductors, a signal switch on the locomotive for interrupting the circuit through the signal device, a plurality of current responsive signal devices on the cars of the trainconnected across the said conductors and operative when deenergized to give a signal, a selector SWltCh on each car for selectively connecting the car signal devices in circuit with the locomotive signal devices and the said supply meanswhereby the carv signal devices are under the control of the signal switch on the locomotive, or shunting the locomotive signal device and the locomotive signal switch from the circuit containing its respective signal device, and

switch means on each car in the circuit containing the signal device thereon, operative to establish an energizedcircuit through the respective signal device on the car and the signal device and signal switch on the locomotive regardless of the operative position of the respective selector switch.

In testimony whereof I have hereunto set my hand, this 7th day oi March, 1929.

' THOMAS H. THOMAS. 

